WO 03/077505 discloses a mobile communication terminal comprising a plurality of lights and means for controlling the activation of the lights. An audio signal, e.g. from a ringing tone, is fed to a signal processor that filters the signal and controls the activation of the lights to let the phone act as a light organ.
The Musical Instrument Digital Interface (MIDI) is an internationally accepted standard for music data for communication between digital music devices. MIDI enables polyphonic musical compositions with a wide variety of different sounds. This means that multiple tones can be played at the same time using predefined instrument sounds such as piano, guitar, violin, drums, etc. The information transmitted between MIDI devices is in the form of MIDI messages, which encode different aspects of sound such as pitch and volume as 8-bit bytes of digital information. MIDI devices can be used for creating, recording and playing back music that is stored as a MIDI file (multiple MIDI messages). Using the MIDI standard, sound cards in computers, synthesizers, and sequencers can communicate with each other, either keeping time or actually controlling the music created by other connected equipment. The message types in a MIDI sequence can be divided in channel messages and system messages. Channel messages apply to a specific channel, and the channel number is included in the status byte for these messages. System messages are not channel specific, and no channel number is indicated in their status bytes.
Channel messages may be further classified as being either channel voice messages, or mode messages. Channel voice messages carry musical performance data, and these messages comprise most of the traffic in a typical MIDI data stream. Channel mode messages affect the way a receiving instrument will respond to the Channel Voice messages.
Channel Voice Messages are used to send musical performance information. The messages in this category are the NOTE ON, NOTE OFF, Polyphonic Key Pressure, Channel Pressure, Pitch Bend Change, Program Change, and the Control Change messages.
With the advent of mobile communication terminals provided with synthesizers capable of playing polyphonic ringing tones from e.g. SP-MIDI files the acoustic quality of the terminals has increased rapidly. Scalable polyphony MIDI (SP-MIDI) is a recent enhancement to the MIDI format that makes it particularly suitable for mobile terminals. SP-MIDI functionality is implemented using a new MIDI message called the Maximum Instantaneous Polyphony (MIP) message. The MIP message is used to define the musical arrangement of the SP-MIDI content according to the desired polyphony levels.
EP 1 255 418 discloses a mobile communication terminal capable of playing ringing tones from MIDI files. The mobile terminal is also provided with a plurality of lights that can be activated by the processor. The document proposes to control the activation of the lights in a MIDI file. Hereto, the lights are implemented as an instrument, with each light seen as a different note. This would however require a modification of the MIDI standard, in particular of the SP-MIDI standard, since none of the instruments (also referred to as timbres or patches) presently defined in these standards are lights. The modification of such a standard is a complicated procedure that involves many parties with different interests, and can—if it succeeds at all—take a very long time. Further, different terminal models are likely to have varying light arrangements, an aspect that would be difficult to deal with when the lights are defined as an instrument in the standard, since this would require the terminals to be provided with lights in a more uniform manner.